Relief valve for preventing the bursting of liquid containers



Feb. 8, 1938. v. MERRITT 2,107,870

RELIEF VALVE FOR PREVENTING THE BURSTING OF LIQUID CONTAINERS FiledSept. 14, 1933 INVENTOR J5 Vernal a Merritt ATTORNEYS bfsuch valve. 1HOne object is toimprove the means'for pre,

:iPatented Feb. s, 71938 i STATES PSATENTV OFFICE RELIEF VALVE FORPREVENTING THE ,BURSIING. F LIQUID ooN'rmNEns I Yernon Merritt,Montgomery, Ala. Application September-I14, 1933, :Serial No. 689,422

11 Claims. (o1. 131 34.-s)

. invention relates to, a device in the nature of-an automaticreliefvalve for preventing the bursting of liquid containers, such aspipes,fit- .tings, radiators, water cooled engine blocks and- '5 thelike, whensubjected to freezing temperature.

in my Letters Patent No. 1,851,202, issued to me on'March 29th, 1932, Ihave shown and de- .-,,scribed a relief valve of the plug type mountedin alsuitable seat so as to penetrate into the container"beyond theinitial'freezing zone and hav- Sing itsportion that; is exposedwithinthe container coveredwith a material adapted to prevent theestablishment of a frostbond and pref- ,7 I erably to insulate the valveso as to retard radia lti011 of heat from the'liquid in contact-with it.

I j and thereby slow up the formation of ice about the inner. end of thevalve. The present inven- ,;tion;contemplates certain improvementshereinafter described in the construction and design 7 venting theice-or frozen liquidasdtfforms ingthepontainer from adhering'to,or'forming'a ybond with, the valveso as to prevent it;frbm op- .eratingfreely. I have discovered that this ob- ,:,;j tis best attained by;forming the valve of '9. material of low heat conductivitysuch asbakelite I or other suitablenon-conducting substance which preferablyhas a highly polished exterior.

. to reduce the adherenceof the ice theretoa I My invention furthercontemplates that the I valve, or it'score whetherof conducting or non--v conducting material, may have applied over its 1 highly polished orvery smooth exterior a jacket or cover of soft resilient rubber having avery smooth or 'glazedqsurface, which -will exposetojthe;liquidenotirregular or roughsurface to which the ice would adhere;It is contemplated; vthat such a iacketshall be ,free to bothicontract0 or to creep on the valve as-the ioelformsabout it sojas to give andpreventthe formatlonjofan icebond with it that will interfere with itsfree functioning. I

' Another objectis ject beyond the seat and initial ice zone'into thebody oi vliquid in the, container which will be brought. underincreasing pressure as the freezingoftlie liquid in the containerprogresses.

5 Another object is to latch thevalvein seated position, the latchbeingreleasable under abnormally. highinternalpressure to allow thevalve "toifiopen fully and drain the container without f having; a.repeated or periodic operation.

o o toeprovide only a short taper-j seat forthe valve, leaving its'innerend to pro-p purposes described having a positive means for retaining itin itsclosed position, such means however. being releasable'whensubjected to abnormal pressures withinthe container so as to reduce orrelieve the internal pressure. 1 5 A further object of my invention isto provide a spring pressed valve of the character described with areleasable spring meanswhich when subjected to abnormal internalpressures will act either to permit the valve'to open freely and fully10 .which become disengaged when the valve is forced open but which areadapted to be readily reengaged to reseat the valve in operatingposition. A further important object is to so design the mounting fortheyieldable or spring means, that, holdsthe valve in working position asto avoid the possibility of ice forming from the escaping liquid so asto block the valves opening move- 30 ment. I p 1 I V A further-object ofmy invention is to adapt the various yieldable .valve mounting meansshown to permit the valve to be opened freely manually-thus adapting itto serve as a drain cock.

7 My-invention further comprises the novel details of constructionandarrangements of parts, which in their preferred embodiments only areillustrated in the accompanying drawing which 40v forms apart of thisspecification, and in which:- Fig. l is a top plan view of oneembodiment of myinvention having a spring latch retainer for a rubbercoatedvalve. i

. Fig.2is aside elevation of the valve and. its seatas shown in Fig. 1.

Fig 3is a vertical sectional view taken on the line III-III of Fig. 1.

Fig, 4 illustrates an embodiment of my invention wherein a bakelitevalve is held seated by a spring having a releasable seat which issnapped loose when the valve is forced open.

Fig. 5shows a plug valve of heat non-conducting material mounted in amotor block section by a releasable metallic disk forced into the holethrough whichthe valve projects into the liquid surrounding the motorcylinders.

Similar reference numerals refer to similar parts throughout thedrawing.

In the embodiment of my invention illustrated in Figs. 1 to 3, Iconventionally illustrate at It a wall of any liquid container such as apipe, a vessel of any character, a radiator, a motor block, etc. A holeis bored and tapped therein to receive the reduced threaded shank ll ofa valve seat member l2 which has an inwardly tapering bore [3 serving asa seat for my automatic relief valve.

The relief valve, as shown in these views, has a body 14 which may be ofmetal or other conducting material but which is preferably of heatnon-conducting material'such as bakelite. This body is tapered toconform to the taper'of its seat I3 and its exterior surface is madesmooth and highly polished. Over such exterior surface I apply a heatnon-conducting sleeve or jacket l5 which is preferably very resilientrubber with its exterior surface finished so very smooth as to preventor resist effectively the formation of a frost bond therewith. The valvebody has at its upper end outside of the valve seat an annular groove Isto "receive an internal. shoulder formed in the rubbersleeve so as tolock the sleeve in position. The upper end of the valve is provided withspaced lugs ll to receive between them the end I8 of an S-shaped' leverand to hold thepivot pin l9 which connects the valve to this lever. Thevalve seat l2 has out-turned marginal bearing arms 20 between which thelever is pivotally mounted by a pin 2| with its free endbent up toform ahandle 22.

A spring 23 is formed of' bent wire arranged to provide spaced parallelsides eachhaving a coil orhelix therein and each connected at its lowerend tothe base of the adjacent bearing arm 26] "and at its upper end toa cross arm or latch 24 which is adapted to be engaged-and retainedbetween the upper ends of the bearing arms as a keeper 25 and theupwardly curving closed position against jolts or accidental dis-'placement.

The valve projects substantially beyond its seat and its smooth innerend penetrates into the liquid in the containerbeyond the zone o'finitial freezing thereof so as to be exposed to the increasing pressureon the unfrozen liquid as the freezing action progresses.

The valve is so mounted that there is no possibility of liquid escapingpast it becoming trapped or held so as to freeze and block the valvesopening movement. p

Having thus latched the valve in its seated position, as the internalpressure rises due to freezing, the unfrozen liquid exerts an increasingforce acting onthe'inner end of 'the tapered valve to unseat it; When apressure sufiicient to unseat the valve exists, the valve movesoutwardly forcing the spring latch arm 24 over its keeper 25 whereuponthe spring will snap against the valve lever and force the valve toswing outwardly clear of its seatand permit the free outflow of liquidsufiicient to protect the container against bursting. The spring willhold the valve open but it can be readily reset by forcing the valve toits seat and again engaging the latch arm 24 with its keeper 25 as shownin Fig. 2.

At any time the lever end 22 can be pressed down manually to trip thelatch and open the valve to drain the container or relieve its internalpressure.

In Fig. 4 I show a simpler valve construction 3 has an annular flange 32rising therefrom concentric with and spaced from the seat 3! so that agasket 33 may be placed under the valve flange 29. A cap 34 of springmetal slit to provide resilient arms 35 will snap over the flange 32 andreleasably interlock therewith. The wide base coil of a spiral spring 36is seated in a bead in the top of the cap and its inner end surroundstheboss 30 on the valve.

The spring is preferably' interlocked with both the cap and boss to holdthe valve and cap assembled. The topof the boss is spaced from the capand the spring engagement between the cap and flange 32 is sufficientlystrong 'to exert a pressure through spring- 36 on the valve that willhold it to its seat against any but abnormally high internal pressures.

In operation, the valve assembly is readily mounted by pressing thevalve to its seat until the cap is engaged with flange 32. When freezingoccurs and the internal pressure on the unfrozen liquid rises, the valvewill be forced outwardly and in so moving its boss will engage the cap34 and force it loose, whereupon the liquid will freely escape from thecontainer.

In Fig. 5 I show a further modification of my invention-. Here anopening 37 is formed in the wall of a motor block 38 and a metallicmountin-g disk 39 is forced into such opening until it seats firmlybutreleasably therein. The disk carries a plug valve 40, ofn'on-heat-conducting material or comprising such material, which isdisposed to project substantially into theliquid in the motorblock toapoint well beyond the zone of initial freezing indicated by the dottedline 4|. Preferably, this plug will prevent access of the internalliquid to the disk. The opening 31 may be reduced at its inner end toform a tapered seat 42 for the valve 69. The internal pressure will riseas the freezing progresses until it ishigh enough to exert a force onthe plug that will unseat the disk and expel the valve to permitthe'unfrozen liquid to escape before the container bursts.

r In the embodiments of my invention hereinbefore described, noprovision is made for what may be termed the periodic openingand closingof thevalve to progressively relieve internal-pressure as the freezingproceeds as that action may beaccomplished by the utilization of thevalves shown with the type of spring mounting described by my LettersPatent aforesaid.

'Without further description, it is thought that Y the featuresand'advantages of the invention will freeze plug mounted in the wall ofsaid container,

and havinga highly polished exterior surface of a material resistant tothe establishment therewith of a frost bond, which surface is adapted tof project intothe liquid within the container beyond the zone of initialfreezing thereof, and retaining means coacting with the container andplug to hold the latter seated against normal 7 internal pressures andadapted to permit the expulsion of the plug from its seat to freelydrain said container., I

2. In a means to prevent liquid containers from bursting under freezingstrains, a freeze plug adapted to be mounted in the wall of a containerand having its inner end which is adapted to project into the liquidwithin the container high- 1y. polished, and a rubber sleeve coveringsaid polished portion and itself provided with a polished exteriorsurface where exposed to the liquid.

3. In combination, a liquid container and a poor-heat-conducting freezeplug mounted in a wall of said container and adapted to project a '20.

substantial distance thereinto, whereby pressures developed by theprocess of freezing will displace said plug, and spring means normallyholding said plug in said wall and capable of withdrawing it when onceunseated.

- 4. In a device of the class described, a conical I valve. responsiveto the pressure exerted by a v,freezing liquid, a-valve seat memberhaving a conical valve seat, said conical valveadapted to 3 0. crum andconnected to said valve, and spring engage, said seat; afulcrum carriedby said seat member, a lever pivotally mounted on said fulmeans actingupon said lever to normally hold said valve in seated engagement withsaid valve seat and when released to fully withdraw the valve from itsseat.

5. In a device of the class described, a valve responsive to thepressure exerted by a freezing liquid, 'avalve seat member having anexteriorly threaded boss and a valve seat, a fulcrum carried by saidmember, a lever pivotally mounted on said fulcrum, said valve connectedto one end of [said lever, said valve being of a sufiicientlength toextend a substantial distance beyond its seat into the vessel, andspring means for normally retaining said valve in engagement with itsseat.

a '6. In a'device of the class described, a conical "valve responsive tothe pressure exerted by. a

1 a substantial distance beyond its seat into the freezing liquid,spring means for normally retaining said valve in seated engagement withsaid valve'seat, and a handle portion on said lever to provide for themanual release of said valve.

7. A valve responsive to the pressure exerted by a freezing liquidcomprising a valve seat, a valve operatively associated therewith, saidvalve being of a pOor-heat-conducting material and having a covering ofsmooth rubber of high elasticity, and retaining means for holding saidvalve in seated engagement with said valve seat against normal internalpressures.

8. In a device of the class described, a valve responsive to thepressure created by a freezing liquid, a valve seat member, a leverconnected to said valve and having a big'ht portion, a fulcrum carryingmember integrally formed with said valve seat member and rockablysupporting said lever, said fulcrum carrying member having a portionprojecting above said bight portion, and

a spring mounted upon said seat member and having a latch portionengageable between said bight portion and-said fulcrum carrying memberprojecting portion for normally holding said valve in seated engagementwith said valve seat.

9. A valve responsive to the pressure exerted by a freezing liquidcomprising a valve seat, a valve operatively associated therewith andhaving a tapered inner end adapted to be exposed to said liquid,comprising an exterior polished surface of a poor-heat-conductingmaterial and having a covering for said surface of smooth rubber of highelasticity, and retaining means for holding said valve in seatedengagement with said valve seat against normal internal pressures.

10. In combination with the relief port of a liquid container, a freezeprotection plug inserted in said port, the plug having an elongatedrigid tapering core adapted when the valve is seated to project into thecontainer beyond the zone of initial freezing, the plug having itssurface polished and a soft polished rubber sleeve fitted over thepolished plug and interposed between it and the walls of the relief portand the liquid in the container.

11. The combination with a liquid container having a relief port, of atapered expellable freeze plug composed of poor-heat-conducting materialwith a highly polished exterior surface seated in said port and adaptedto project beyond same into the liquid in the container, and means tohold said plug against expulsion by normal internal pressures withinsaid container.

VERNON MERRI'IT.

